Hi, I am new, but eager to learn. Will be buying a kit soon from my local brew supply store but I am trying to determine the best size stock pot. I know the brand that I want but don't know a good size. I will be doing 5 gallon extract batches but possibly some smaller 2 or 2.5 gallon batches too. I think eventually I will want to get into partial mash and full grain. So, is there a one size fit all (which I don't think there is). Assuming there isn't a one size fit all, which size would you recommend someone to start with?

I was actually thinking a 40 quart as I think it will be some time before I am past anything more than extract or partial mashes. Being I don't think I will do more than 5 gallon batches, I would hope a 10 gallon kettle would work? My bigger concern is actually the smaller batches. If I am only doing 2 gallons, how much efficiency am I going to lose with such a "large" kettle? I thought about an 8 gallon but suspect that would be pushing the limits with a full 5 gallon brew.

As far as the heat source, natural gas stove for the time being, perhaps a dedicated propane burner after I have a few batches under my belt.

Generally 'efficiency' is an all grain issue and concerns what percentage of available sugars are being gathered. With extract you don't have that issue. But surface area compared to volume can increase evaporation rates I suppose. I would do a two gallon boil in a three - five gallon pot. A five gallon boil should be fine in an eight gallon pot.

The rule of thumb in professional brewing is 50% extra volume compared to the cast wort volume (not the packaging volume). Since evaporation rates are typically so much higher in home brewing, I'd say 50% is about the minimum. I do 6 gal batches and a 10 gal kettle gets uncomfortably full.

Even doing extract batches you will eventually reach the point where you will at least want the option to do full boils, so I'd go ahead and start out with a pot big enough to do a full boil. A larger pot will make your life easier but at a minimum you need space for 6.5 gallons of wort (that gives you enough for 1.5 gallons of boiloff on a 90 minute boil) plus space for the boil to foam up. I'd look at trying to start off with an 8 gallon pot (or whatever the closest liter equivalent is).

If you have a natural gas stove you can probably get that 8 gallon pot boiling on your stove with 6.5 gallons of wort. If you don't have natural gas then the most financially efficient option would be to buy a propane turkey fryer today. If you are doing smaller batches or partial boils you can use the turkey fryer pot on your electric stove but once you reach the point where you are doing larger boils you can use the turkey fryer outdoors in the same pot. However the turkey fryer pots are very tall so if your stove doesn't have enough clearance for the pot you will have to go a different route.

I started out using a 5 gal. pot to do partial boils. It only cost $20, so no big deal. I eventually bought a turkey fryer setup to brew outdoors and it came with a 7 gal. pot. I still had to do partial boils and top off a bit afterward, but it worked great. Eventually I moved to a converted keg for a kettle, but I still use the 7 gal. to heat water for the mash and the 5 gal. for the occasional decoction or to make stock. So there was no downside and no money lost by going incrementally. You might want to consider that.